qsqldatabase.cpp

奇趣公司比较新的qt/emd版本

*/

void QSqlDatabase::removeDatabase(const QString& connectionName)
{
    QSqlDatabasePrivate::removeDatabase(connectionName);
}

/*!
    Returns a list of all the available database drivers.

    \sa registerSqlDriver()
*/

QStringList QSqlDatabase::drivers()
{
    QStringList list;

#ifdef QT_SQL_PSQL
    list << QLatin1String("QPSQL7");
    list << QLatin1String("QPSQL");
#endif
#ifdef QT_SQL_MYSQL
    list << QLatin1String("QMYSQL3");
    list << QLatin1String("QMYSQL");
#endif
#ifdef QT_SQL_ODBC
    list << QLatin1String("QODBC3");
    list << QLatin1String("QODBC");
#endif
#ifdef QT_SQL_OCI
    list << QLatin1String("QOCI8");
    list << QLatin1String("QOCI");
#endif
#ifdef QT_SQL_TDS
    list << QLatin1String("QTDS7");
    list << QLatin1String("QTDS");
#endif
#ifdef QT_SQL_DB2
    list << QLatin1String("QDB2");
#endif
#ifdef QT_SQL_SQLITE
    list << QLatin1String("QSQLITE");
#endif
#ifdef QT_SQL_SQLITE2
    list << QLatin1String("QSQLITE2");
#endif
#ifdef QT_SQL_IBASE
    list << QLatin1String("QIBASE");
#endif

#ifndef QT_NO_LIBRARY
    if (QFactoryLoader *fl = loader()) {
        QStringList keys = fl->keys();
        for (QStringList::const_iterator i = keys.constBegin(); i != keys.constEnd(); ++i) {
            if (!list.contains(*i))
                list << *i;
        }
    }
#endif

    DriverDict dict = QSqlDatabasePrivate::driverDict();
    for (DriverDict::const_iterator i = dict.constBegin(); i != dict.constEnd(); ++i) {
        if (!list.contains(i.key()))
            list << i.key();
    }

    return list;
}

/*!
    This function registers a new SQL driver called \a name, within
    the SQL framework. This is useful if you have a custom SQL driver
    and don't want to compile it as a plugin.

    Example:
    \code
    QSqlDatabase::registerSqlDriver("MYDRIVER",
                                    new QSqlDriverCreator<MyDatabaseDriver>);
    QSqlDatabase db = QSqlDatabase::addDatabase("MYDRIVER");
    \endcode

    QSqlDatabase takes ownership of the \a creator pointer, so you
    mustn't delete it yourself.

    \sa drivers()
*/
void QSqlDatabase::registerSqlDriver(const QString& name, QSqlDriverCreatorBase *creator)
{
    delete QSqlDatabasePrivate::driverDict().take(name);
    if (creator)
        QSqlDatabasePrivate::driverDict().insert(name, creator);
}

/*!
    \threadsafe

    Returns true if the list of database connections contains \a
    connectionName; otherwise returns false.

    \sa connectionNames(), database(), {Threads and the SQL Module}
*/

bool QSqlDatabase::contains(const QString& connectionName)
{
    return dbDict()->contains_ts(connectionName);
}

/*!
    \threadsafe

    Returns a list containing the names of all connections.

    \sa contains(), database(), {Threads and the SQL Module}
*/
QStringList QSqlDatabase::connectionNames()
{
    return dbDict()->keys_ts();
}

/*!
    \overload

    Creates a QSqlDatabase connection that uses the driver referred
    to by \a type. If the \a type is not recognized, the database
    connection will have no functionality.

    The currently available driver types are:

    \table
    \header \i Driver Type \i Description
    \row \i QDB2     \i IBM DB2
    \row \i QIBASE   \i Borland InterBase Driver
    \row \i QMYSQL   \i MySQL Driver
    \row \i QOCI     \i Oracle Call Interface Driver
    \row \i QODBC    \i ODBC Driver (includes Microsoft SQL Server)
    \row \i QPSQL    \i PostgreSQL Driver
    \row \i QSQLITE  \i SQLite version 3 or above
    \row \i QSQLITE2 \i SQLite version 2
    \row \i QTDS     \i Sybase Adaptive Server
    \endtable

    Additional third party drivers, including your own custom
    drivers, can be loaded dynamically.

    \sa {SQL Database Drivers}, registerSqlDriver(), drivers()
*/

QSqlDatabase::QSqlDatabase(const QString &type)
{
    d = new QSqlDatabasePrivate();
    d->init(type);
}

/*!
    \overload

    Creates a database connection using the given \a driver.
*/

QSqlDatabase::QSqlDatabase(QSqlDriver *driver)
{
    d = new QSqlDatabasePrivate(driver);
}

/*!
    Creates an empty, invalid QSqlDatabase object. Use addDatabase(),
    removeDatabase(), and database() to get valid QSqlDatabase
    objects.
*/
QSqlDatabase::QSqlDatabase()
{
    d = QSqlDatabasePrivate::shared_null();
    d->ref.ref();
}

/*!
    Creates a copy of \a other.
*/
QSqlDatabase::QSqlDatabase(const QSqlDatabase &other)
{
    d = other.d;
    d->ref.ref();
}

/*!
    Assigns \a other to this object.
*/
QSqlDatabase &QSqlDatabase::operator=(const QSqlDatabase &other)
{
    qAtomicAssign(d, other.d);
    return *this;
}

/*!
    \internal

    Create the actual driver instance \a type.
*/

void QSqlDatabasePrivate::init(const QString &type)
{
    drvName = type;

    if (!driver) {
#ifdef QT_SQL_PSQL
        if (type == QLatin1String("QPSQL") || type == QLatin1String("QPSQL7"))
            driver = new QPSQLDriver();
#endif
#ifdef QT_SQL_MYSQL
        if (type == QLatin1String("QMYSQL") || type == QLatin1String("QMYSQL3"))
            driver = new QMYSQLDriver();
#endif
#ifdef QT_SQL_ODBC
        if (type == QLatin1String("QODBC") || type == QLatin1String("QODBC3"))
            driver = new QODBCDriver();
#endif
#ifdef QT_SQL_OCI
        if (type == QLatin1String("QOCI") || type == QLatin1String("QOCI8"))
            driver = new QOCIDriver();
#endif
#ifdef QT_SQL_TDS
        if (type == QLatin1String("QTDS") || type == QLatin1String("QTDS7"))
            driver = new QTDSDriver();
#endif
#ifdef QT_SQL_DB2
        if (type == QLatin1String("QDB2"))
            driver = new QDB2Driver();
#endif
#ifdef QT_SQL_SQLITE
        if (type == QLatin1String("QSQLITE"))
            driver = new QSQLiteDriver();
#endif
#ifdef QT_SQL_SQLITE2
        if (type == QLatin1String("QSQLITE2"))
            driver = new QSQLite2Driver();
#endif
#ifdef QT_SQL_IBASE
        if (type == QLatin1String("QIBASE"))
            driver = new QIBaseDriver();
#endif
    }

    if (!driver) {
        DriverDict dict = QSqlDatabasePrivate::driverDict();
        for (DriverDict::const_iterator it = dict.constBegin();
             it != dict.constEnd() && !driver; ++it) {
            if (type == it.key()) {
                driver = ((QSqlDriverCreatorBase*)(*it))->createObject();
            }
        }
    }

#ifndef QT_NO_LIBRARY
    if (!driver && loader()) {
        if (QSqlDriverFactoryInterface *factory = qobject_cast<QSqlDriverFactoryInterface*>(loader()->instance(type)))
            driver = factory->create(type);
    }
#endif // QT_NO_LIBRARY

    if (!driver) {
        qWarning("QSqlDatabase: %s driver not loaded", type.toLatin1().data());
        qWarning("QSqlDatabase: available drivers: %s",
                        QSqlDatabase::drivers().join(QLatin1String(" ")).toLatin1().data());
        driver = shared_null()->driver;
    }
}

/*!
    Destroys the object and frees any allocated resources.

    If this is the last QSqlDatabase object that uses a certain
    database connection, the is automatically closed.

    \sa close()
*/

QSqlDatabase::~QSqlDatabase()
{
    if (!d->ref.deref()) {
        close();
        delete d;
    }
}

/*!
    Executes a SQL statement on the database and returns a QSqlQuery
    object. Use lastError() to retrieve error information. If \a
    query is empty, an empty, invalid query is returned and
    lastError() is not affected.

    \sa QSqlQuery, lastError()
*/

QSqlQuery QSqlDatabase::exec(const QString & query) const
{
    QSqlQuery r(d->driver->createResult());
    if (!query.isEmpty()) {
        r.exec(query);
        d->driver->setLastError(r.lastError());
    }
    return r;
}

/*!
    Opens the database connection using the current connection
    values. Returns true on success; otherwise returns false. Error
    information can be retrieved using lastError().

    \sa lastError() setDatabaseName() setUserName() setPassword() setHostName() setPort() setConnectOptions()
*/

bool QSqlDatabase::open()
{
    return d->driver->open(d->dbname, d->uname, d->pword, d->hname,
                            d->port, d->connOptions);
}

/*!
    \overload

    Opens the database connection using the given \a user name and \a
    password. Returns true on success; otherwise returns false. Error
    information can be retrieved using the lastError() function.

    This function does not store the password it is given. Instead,
    the password is passed directly to the driver for opening the
    connection and it is then discarded.

    \sa lastError()
*/

bool QSqlDatabase::open(const QString& user, const QString& password)
{
    setUserName(user);
    return d->driver->open(d->dbname, user, password, d->hname,
                            d->port, d->connOptions);
}

/*!
    Closes the database connection, freeing any resources acquired, and
    invalidating any existing QSqlQuery objects that are used with the
    database.

    This will also affect copies of this QSqlDatabase object.

    \sa removeDatabase()
*/

void QSqlDatabase::close()
{
    d->driver->close();
}

/*!
    Returns true if the database connection is currently open;
    otherwise returns false.
*/

bool QSqlDatabase::isOpen() const
{
    return d->driver->isOpen();
}

/*!
    Returns true if there was an error opening the database
    connection; otherwise returns false. Error information can be
    retrieved using the lastError() function.
*/

bool QSqlDatabase::isOpenError() const
{
    return d->driver->isOpenError();
}

/*!
    Begins a transaction on the database if the driver supports
    transactions. Returns true if the operation succeeded; otherwise
    returns false.

    \sa QSqlDriver::hasFeature(), commit(), rollback()
*/

bool QSqlDatabase::transaction()
{
    if (!d->driver->hasFeature(QSqlDriver::Transactions))
        return false;
    return d->driver->beginTransaction();
}

/*!
    Commits a transaction to the database if the driver supports
    transactions and a transaction() has been started. Returns true if
    the operation succeeded; otherwise returns false.

    Note that on some databases, this function will not work if there
    is an active QSqlQuery on the database. Use the lastError()
    function to retrieve database-specific error data about the error
    that occurred.

    \sa QSqlDriver::hasFeature() rollback()
*/

bool QSqlDatabase::commit()
{
    if (!d->driver->hasFeature(QSqlDriver::Transactions))
        return false;
    return d->driver->commitTransaction();
}

/*!
    Rolls a transaction back on the database if the driver supports
    transactions and a transaction() has been started. Returns true
    if the operation succeeded; otherwise returns false.

    \sa QSqlDriver::hasFeature() commit()
*/

bool QSqlDatabase::rollback()
{
    if (!d->driver->hasFeature(QSqlDriver::Transactions))
        return false;
    return d->driver->rollbackTransaction();
}

/*!
    Sets the connection's name to \a name. This must be done before
    the connection is opened or it has no effect; (or you can close()
    the connection, call this function and open() the connection
    again). The name is database-specific.

    For the QOCI (Oracle) driver, the database name is the TNS
    Service Name.

    For the QODBC driver, the \a name can either be a DSN, a DSN
    filename (in which case the file must have a \c .dsn extension),
    or a connection string.

    For example, Microsoft Access users can use the following
    connection string to open an \c .mdb file directly, instead of
    having to create a DSN entry in the ODBC manager:

    \code
    ...
    db = QSqlDatabase::addDatabase("QODBC");
    db.setDatabaseName("DRIVER={Microsoft Access Driver (*.mdb)};FIL={MS Access};DBQ=myaccessfile.mdb");
    if (db.open()) {
        // success!
    }
    ...
    \endcode

    There is no default value.

    \sa databaseName() setUserName() setPassword() setHostName() setPort() setConnectOptions() open()
*/

void QSqlDatabase::setDatabaseName(const QString& name)
{
    if (isValid())
        d->dbname = name;
}

/*!
    Sets the connection's user name to \a name. This must be done
    before the connection is opened or it has no effect (or you can
    close() the connection, call this function and open() the
    connection again).

    There is no default value.

    \sa userName() setDatabaseName() setPassword() setHostName()
    setPort() setConnectOptions() open()
*/

void QSqlDatabase::setUserName(const QString& name)
{
    if (isValid())
        d->uname = name;
}

/*!
    Sets the connection's password to \a password. This must be done
    before the connection is opened or it has no effect (or you can
    close() the connection, call this function and open() the
    connection again).

    There is no default value.

    \warning This function stores the password in plain text within
    Qt. Use the open() call that takes a password as parameter to
    avoid this behavior.

    \sa password() setUserName() setDatabaseName() setHostName() setPort() setConnectOptions() open()
*/

void QSqlDatabase::setPassword(const QString& password)
{
    if (isValid())
        d->pword = password;